A malignant breast lump generally refers to breast cancer, along with the less common breast sarcoma. Breast cancer has symptoms such as breast lump, breast skin abnormality, nipple and areola abnormality, nipple overflow, axillary lymph node enlargement, etc. Distant metastasis occurs in the late stage, which is accompanied by different manifestations in other organs. 1. Breast lump: patients with breast cancer may have breast lump in early stage, which is usually located in the upper outer quadrant, usually unilateral, hard, irregular edge, not smooth surface, not easy to be pushed, usually painless lump, and a few of them are accompanied by hidden pain or stinging pain. 2. Breast skin abnormality: Cancer cells block lymphatic vessels, resulting in lymphedema and orange peel-like change of breast skin. When the cancer cells infiltrate into the skin and grow, scattered hard skin nodules will be formed around the lesion and solid skin nodules will appear. 3. Abnormalities of nipple and areola: when the mass invades the nipple and subareolar region, it may pull the nipple, making it concave, deviated, or even completely retracted into the back of areola. 4. Nipple overflow: some patients with breast cancer will have the manifestation of nipple overflow, with the nature of liquid discharged from unilateral breast, which is mostly bloody, plasma and watery secretion. 5. Enlarged axillary lymph nodes: the shedding of cancer cells occurring in breast cancer can invade the surrounding lymphatic vessels, and may also metastasize to the local lymphatic drainage area, with the manifestation of enlarged axillary lymph nodes on the same side. At the same time, malignant breast lumps also have breast sarcoma, breast sarcoma is a rare malignant tumor, manifested as painless lumps in the breast, with high malignant degree, and early hematogenous metastasis, with poor prognosis. When there is a lump in the breast, it is necessary to consult a regular hospital in time to clarify the reason for the formation of the lump, and under the guidance of the doctor for proper treatment.